If I understand your question, I think the step you’re overlooking is the payment on that debt. Unallocated funds represent money in an account that isn’t in a budgeted envelope, so when you added $670 in cash (that presumably wasn’t in a “cash” account in GB) you added funds to your available money, which then became Unallocated.
Here’s an example:
You start with $0 in Unallocated funds, $100 in the bank, and $100 in your Envelopes.
You add $670 to the bank for a total of $770, and now your Unallocated balance goes up to $670.
You charge the $700 to your credit card at the tire store, so now you have $700 in debt BUT you haven’t paid it off yet, so your money in the bank and in Unallocated doesn’t change. In order to make the balances look the way you like, you have two options.
First, you could pay the card and do a debt payment transaction which will decrease your bank account balance AND your debt, (-$700 at the bank, +$700 on the card) OR
Second, you could use your Unallocated money to fill the envelope you used to buy your tires. This will remove it from Unallocated but not change your debt, until you record a payment on the card. Don’t forget to record the tire transaction into that envelope too.
So in summary here’s the order I’d do this:
1-Deposit the cash to the account. I would personally use the “Fill From New Income” option to simplify it; enter the $670 and allocate it to the correct envelope in one step. (your Unallocated won’t change but your tire envelope and your bank account will both go up by $670)
2-Enter the tire transaction on the card from the envelope you just added money to; this will decrease the balance in that envelope and increase your debt but it won’t change your bank account or your Unallocated balance.
3-Make a debt transaction card payment to move money out of the bank and onto the card. This should make everything balance out as you expect.
Hope that helps!